Fluid perfused urethral pressure profilometry and Valsalva leak point pressure: a comparative study in a biophysical model of the urethra

Abstract

In patient studies the correlation between maximum urethral closure pressure (MUCP) and Valsalva leak point pressure (LPP) is meagre at best (r = 0.22-0.50). We therefore studied the relation between MUCP and LPP in a Xexible and extensible model urethra. We applied diVerently sized pressure zones and diVerent degrees of resistance to a biophysical model urethra by stepwise inXating three types of blood pressure cuV placed around the model. At each degree of resistance we measured detrusor LPP, an in vitro equivalent of Valsalva LPP. Subsequently, we recorded the Urethral Pressure ProWle using a water-perfused 5F end-hole catheter at four withdrawal rates and Wve perfusion rates and calculated MUCP. We tested the dependence of LPP on pressure zone length and MUCP on perfusion rate, withdrawal rate and pressure zone length using analysis of variance. We tested the correlation between LPP and MUCP using Pearson's correlation coeYcient and Linear Regression. LPP did not signiWcantly depend on the pressure zone length (P = 0.80) and increased linearly with increasing cuV pressure. MUCP also increased with increasing cuV pressure, however, MUCP signiWcantly depended (P < 0.01) on perfusion rate, withdrawal rate and pressure zone length. MUCP increased with increasing perfusion rate, and decreased with increasing withdrawal rate. In our model urethra MUCP only accurately reXected urethral resistance for a very limited number of combinations of perfusion rate and withdrawal rate. LPP reXected urethral resistance independent of the type of pressure zone.

Does assessing urethral function allow the selection of the optimal therapy for recurrent SUI? Report from the ICI‐RS 2017

“…Given the inherent inaccuracies and variability associated with urethral function tests there is no consensus of opinion whether urethral function should be assessed prior to redo surgery, and if so, which tests should be used. There is some evidence to support the correlation of MUCP and VLPP at different bladder volumes and this is also supported by more recent work in the animal model . In addition MUCP has been shown to correlate with urethral sphincter volumes measured using 3D ultrasound Furthermore, urethral sphincter volume has been shown to be predictive of continence surgery outcome although no such association has been seen with MUCP .…”

Optimum anesthesia for reliable urethral pressure profilometry in female dogs and goats

“…Furthermore, injecting propofol in boluses was associated with unstable myorelaxant action, which increased the variability of measurements obtained under full‐dose propofol in goats and dogs. Repeatability might be improved with a checklist for confirming that standardized conditions are used during recording, including catheter size, type, orientation and withdrawal speed, as well as perfusion rate, patient position, volume of fluid in the bladder, type of anesthesia and level of awareness.…”

“…Furthermore, injecting propofol in boluses was associated with unstable myorelaxant action, which increased the variability of measurements obtained under full-dose propofol in goats and dogs. Repeatability might be improved with a checklist for confirming that standardized conditions are used during recording, including catheter size, type, orientation and withdrawal speed, 23 as well as perfusion rate, patient position, volume of fluid in the bladder, 8 type of anesthesia and level of awareness. Despite confirmed significant depressive effects of anesthetics on urethral pressure, we are convinced that UPP measurements carried out in female goats carried out repeatedly during recovery from propofol is an attractive method for research on cell therapy in urethral sphincter deficiency.…”